


Let's be Bad Together, Make the Devil Smile

by GilgaNyan (NarryEm)



Series: Adventures in Chaldea [7]
Category: Fate/Grand Order, Fate/stay night & Related Fandoms
Genre: (a tiny bit), Alternate Universe - Canon Divergence, Domestic Fluff, Fate, Fluff and Smut, Kissing, M/M, Mild Sexual Content, Non-Consensual Kissing, Self-cest, Sensuality, Slice of Life
Language: English
Status: Completed
Published: 2018-07-27
Updated: 2018-07-27
Packaged: 2019-06-15 08:51:46
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 3,704
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15409389
Author URL: https://archiveofourown.org/users/NarryEm/pseuds/GilgaNyan
Summary: Ritsuka did not mean for this to happen.All he did was (attempt to) practice using magic circles and that somehow resulted in the summoning of Gilgamesh as he was in his physical prime, the ruthless tyrant King of Heroes who has no equal in the Throne of Heroic Servants.  Of course, it does not bode well that the golden Archer sees everyone as mongrels who hold no meaning.  To no-one’s surprise, seeing his older self romantically involved with a brat of a Master infuriates him to no end.Perhaps what the Archer needs is some one-on-one time with someone to his liking.





	Let's be Bad Together, Make the Devil Smile

**Author's Note:**

> title from "Bad Together" by Dua Lipa ~~she's so hot and has the voice I love like hot dayum~~
> 
>  
> 
> I never thought of including Archer Gil but this prospect is too good to pass up on.  Thanks to the commenter who brought this up in the last fic! Also, the more gay ships we have the better, am I right!

 

 

The day began like any other ordinary day in Chaldea.  Ritsuka woke up slightly later than the usual with Gilgamesh in his arms, who had been playing with Ritsuka’s hair idly as he waited for the young mage to wake.  He was greeted with a good-morning kiss, followed by a quick round of sex.  By the time the two of them made their way to the canteen, most of the Servants had already eaten and left.  The remaining Servants were Ozymandias, Mash, and Emiya (who was cleaning up and doing the dishes).  Thankfully, the rest of the Heroic Spirits had grown used to Gilgamesh in the past few weeks enough to not heed much attention when they saw him in his adult form.  Ritsuka suspected that some of the Servants were even aware of what kind of relationship their Master and the Caster had but none of them seemed to mind it.  (Ritsuka had also noticed that Gawain had started to frown significantly less frequently whenever he saw the Caster.)

 

In the afternoon, Ritsuka decided to work on his magic training.  He wasn’t good in any particular art, so he began with magic circles since he hardly had any practice with those.  He copied a few of the designs from what appeared to be a text book and muttered the incantations written below.  Nothing happened, which he interpreted to mean that he failed.

The thought dissipated quickly when he heard a loud commotion coming from the general area of the canteen.  He heaved a sigh and hurried over to the canteen.  At times, being a Master felt like a being a school teacher.  If there was any sign of strife amongst the Servants, it was up to Ritsuka to see to a peaceful resolve.

Before his eyes was a rather odd scene.  In the middle of the throng of Servants was a Servant clad in a golden armour with golden hair and piercing bloodred eyes.  Emiya had his favourite pair of swords out, ready to strike at any moment.  Cú Chulainn had taken a stance in front of Emiya, presumably to stop the Archer from lashing out against the new Servant, although a borrowed spear in his hand told a different story.  Arthur Pendragon—who joined them only a week ago—also had his sword drawn.

“My, my, my,” the Heroic Spirit uttered, his voice dripping with disdain and, at the same time, irresistible sensuality.  “This is hardly a grand welcome befitting of a King.  Shall I greet you mongrels with my weapons as well?”

“Try that and I will rip your arm off again,” Emiya growled.

“Whoa, whoa, hold your horses!” Ritsuka shouted, squeezing past the Servants to jump in front of Emiya.  He felt a strong sense of déjà vu at all of this.  Last time, however, Emiya had not been in the room to be this aggressive towards the Servant in question.

Gilgamesh shook his head, gliding through the crowd gracefully.  ‘I cannot believe that you managed to summon another version me, Ritsuka.  He’ll be a troublesome one to control.  This is me before I went on the journey to the Netherworlds and travelled throughout realms to learn and eventually become a wise king.  He is ruthless, cocky, and looks down upon everyone because he believes himself to be the ruler above all.”

The other Gilgamesh glared at his Caster self.  Cú Chulainn stepped up next to the King.  He glared at the golden Archer as he growled out, “Yeah, this one was a pain to deal with, little lad.  Best you send him back to the hellhole he crawled out of.”

“You dare conspire to dismiss me in front of me, dog?” Gilgamesh snarled.  Cú Chulainn curled his lips in distaste.

“Stop stealing my lines,” Caster Gilgamesh sighed, shaking his head in an exasperated manner again.  “Ritsuka.  Surely you do not mean to keep this version of me around?  We have bad blood with the Servants who were summoned in the fourth and fifth Holy Grail Wars of Fuyuki in a parallel world.  Thanks to the summoning system of Chaldea, most of the spirits here retain their memories from those alternate timelines as I have previously explained.  Goldie over there won’t get along with them _at all_.”

“Yes, Master.  Please do send him back to the Throne,” Arthur spoke up.

“If it isn’t the King of Knights himself,” the Archer smirked.  “I guess you were indeed born a man in some of the worlds.”

“What does that mean?” Arthur asked, fingers tightening around the grip of his sword, which was still sheathed, Ritsuka noted with relief.

“Oh, it is nothing of importance to _you_.  I recall that the female version of you who was in Fuyuki rejected my advances several times.  She knew not of the joy of being the one and only consort of the King of Heroes.  I did enjoy trying to slice some sense into her.”

“You . . . !”

“King Arthur, please refrain from any unnecessary bloodshed here,” Caster Gilgamesh requested, his head bowed out of respect to the other King.  “I apologise for his rude mouth.  There is a good reason why my child self hates that one.”

“Do not presume that you know better solely because you happen to be a few years older, Caster,” Archer snorted. 

“I feel bad that Tokiomi didn’t summon the Caster version,” Cú Chulainn muttered under breath.  Emiya nodded in agreement.

“Anyway,” Ritsuka enunciated each syllable.  He went to stand between Archer Gilgamesh and Arthur.  “Since he is here now, let’s try to get along, yeah?”

Emiya narrowed his eyes.  “Doubtful.  But if that is your wish, we have no choice but to comply.”

The golden Archer was positively gloating.  “You mongrels should be honoured to be in my presence.  I shall explore this place now then.  Do not bother me.”

The King disappeared in a shower of golden light, leaving everyone in the canteen confused, angry, agitated, or all of the above (or indifferent if the Servant was Karna).

 

 

 

~

 

 

 

“What’s so bad about the other you?” Ritsuka asks Gil.

The golden-haired boy—Gil adjusted the elixir so he could appear to be in his mid-teens—smiles sinisterly.  “For starters, he ripped the heart out of a little girl to create a vessel for the Holy Grail in some other mage.  He thrust the heart into his ‘Master’s’ chest, which caused him great pain and resulted in his body inflating into an ugly mess of flesh and curses.”

Ritsuka throws up a little in the back of his mouth from hearing that.  “Oh, uhm . . . that _is_ pretty evil.”

“In an alternate timeline, he fed the mud from the corrupted Grail to Arturia—female version of Arthur—and watched her suffer as the curses took over her.   In a different timeline to that, he skewered her with various Noble Phantasms so that she could _‘learn the pleasure from pain before learning the joy of serving under him as his consort as a woman should’_ until Saber’s Master used the Command Seals to have her destroy the Grail with Excalibur.”

“That’s really messed up,” Ritsuka mutters.

“And—”

Ritsuka silences Gil with a kiss on his lips.  “I get it, I get it!  Adult Archer Gilgamesh is Gilga-douche.  He has done a lot of unforgivable things.  But that’s in the past, right?”

Gil shrugs.  “Past can be the present in a parallel world, future in another.  Multiverse is complicated to explain to those who do not possess Sha Naqpa Irumu.  Sometimes we use it unintentionally since this ability does not require a significant amount of mana to activate it.  As a possessor of such ability, I viewed the multiverse’s future whenever I was bored, which was often.  Thus, I came to despise the humanity of the future who were lazy, easily replaceable and unfit for my rule as I saw it at the time.

“Also, in that ‘douche’s’ defense, Gilgamesh as he was in the Fifth Holy Grail War had been corrupted by being borne of the mud from the corrupted Grail.  His already twisted personality was further tainted by the mud of curses of Angra Mainyu in which he bathed.  That only served to amplified his disappointment in today’s humanity and how the Earth was filled with surplus ‘mongrels’ from his perspective.  He thought that only the ‘mongrels’ who could survive the catastrophe he would bring to the world were worthy of his rule.  Cocky AF, am I right?”

Ritsuka chuckles at Gil’s use of modern slang.  “He is.  I’m surprised that you don’t shy from bad-mouthing the other Gilgamesh.”

Gil sighs dramatically.  He lies on his stomach next to Ritsuka, placing his chin between his palms with is elbows lying in his Master’s lap.  “Having a constant reminder of your past is more dauting than I let on, Master.  Just ask Emiya.  He knows that feeling better than I do.   To answer your sentiment, I see the error of my past self’s ways.  If one cannot improve after travelling the realms, he is not fit to be King nor should he pridefully proclaim that he is better than those around him.”

“It’s not fair that you pretty much have it all,” Ritsuka complains half-heartedly.

“If you think that I ‘have it all’, then you also have it all.  I am your lover and Servant so what I have is also yours.”

“How do you always know the perfect thing to say?”

Gil giggled.  “That’s just who I am.  Should I revert to my adult form?  I don’t think I need my mind’s eye to see where this is headed.”

Ritsuka laughs along.  “Ya cheeky boy.”

In the blink of an eye, the boy turns into a man of blinding beauty.

“What was it that you just said, Ritsuka?” the King asks, his hand already at Ritsuka’s waist.  He pushes Ritsuka backwards until Ritsuka’s head touches the headboard on his bed.  “Something about me being cheeky, I believe.”

Ritsuka holds his hands above his head in surrender.  “So damn cheeky.”

Gilgamesh kisses Ritsuka.  He tugs Ritsuka’s lower lip between his teeth playfully as he pulls away.  “Shall we have at it until your teenage hormones have been satiated, Master?”  His flicks his tongue against Ritsuka’s parted lips.

“I don’t think I will ever say no to that invitation,” Ritsuka murmurs, his eyes slipping shut.

“Good.  There is plethora of things left in the world that I have yet to teach you.”  Gilgamesh’s nose trails down the side of Ritsuka’s throat, between his pecs, right along the snail trail until his teeth are centimetres from the tab on Ritsuka’s trousers.

“I’m always willing to learn, _sensei_ ,” Ritsuka replies, his voice coming out breathier than he intended.

“Splendid.  Shall we get started then, Ritsuka~?”

 

 

 

~

 

 

 

Gilgamesh is infuriated, and rightfully so.

First of all, how dare a mutt of a human boy summon him into an age where humanity is already on the verge of extinction?  There can’t be sufficient sources of entertainment if half of what Gilgamesh has observed is true.  He cannot wander the world to see how far humanity has sunk when his days when the world is at a pathetic state already. 

Second of all, the one who walks around wearing his face is happily _in love_ with that brat of a mage, someone who is not worthy of being the Master of a King such as Gilgamesh, even if the Caster version is somewhat weaker thanks to the class’s limitations.  What is even worse is that one of the fakers is a Servant at Chaldea. 

“Sorry,” a voice sounds in front of the golden king. 

Gilgamesh looks at its source.  The voice belongs to Arthur Pendragon, the male version of the Saber from the Grail Wars that he was summoned into.  Going by his outward appearance alone, he lacks the charm that Saber—Arturia Pendragon—possessed.  The only similarity between the two Sabers are the blond hair and their clear green eyes.

As soon as the other Heroic Servant realizes who it is that he nearly bumped into, a frown creases his brows.  The fashion in which he frowns is similar to the Saber that Gilgamesh knew and understood.

“Your apology is accepted, holy sword wielder,” Gilgamesh sneers.

“It is astounding that you are somehow more annoying and hundred times cockier than the Archer summoned in Tokyo,” Arthur comments.

“Do you speak of the Second Holy Grail War in Tokyo, Saber?  That version of me was foolish enough to give you a chance to save your Master.  Had it been me, I would have watched her die slowly and painfully at my leisure.  Although, come to think of it, it may have served as decent entertainment for me back then to have saved Ayaka from the poison so I could kill her later as you begged for her life.”

“You soddin’ bastard!”

Gilgamesh is hardly fazed when the King of Knights brandishes his sword.  “Your severe lack of manners is astounding.  Are you not the legendary King of Britain?”

“As the King of Britain and as an honour-bound Knight of the Round Table, I cannot let insults to my former Master go unpunished,” Arthur retorts.

Gilgamesh cannot hold back his laughter any longer.  He has to maintain proper control of his aether-based body lest he double over with laughter.

“What’s so funny?” Saber growls.

“The mere fact that you have to deign to ask me _‘what’s so funny’_ is the utmost punchline, Saber.  I was right; I will thoroughly enjoy this sojourn.”

“Must I repeat myself?  I inquired: what’s.  so.  funny?”

The King of Uruk surges forwards and backs Saber up against the wall, nearly causing the other blond to knock the back of his head on the corner.  Their armours clink loudly against each other (and against the concrete wall in Saber’s case) as Gilgamesh lowers his face as to look the knight in the eye.

 “This,” the Golden King whispers.

Before Arthur can figure what is about to unfold, soft, dry lips press against his.  The knight’s first and foremost reaction to such advance is repulsion and disgust.  How dare a king belittle another king’s honour this way?  He tries to push away the ancient king but the Archer has him in a vice grip.

Finally, when the kiss is over, the Saber comes away with reddened face and a simmering anger.

“What was that for?” he asks, furiously wiping at his mouth.

“Nothing.  Is this not how you Europeans greet each other?”

“Not on the lips!” Arthur explodes.  Not to mention the crucial fact that the custom was invented by the mainlanders centuries after his time.

The red-eyed devil arches his eyebrows as though this were news to him.  That’s it.  Arthur has had enough.   His hands fly to his hip where his sheath is fastened, more than ready to fight the bastard right here and now.

Watching the King of Knights lose his composure is more amusing that Gilgamesh originally anticipated.  He knows that the prideful knight is less than a step away from striking out with his holy sword.  Just a little more and perhaps this summoning will not be such a bore.

Out of nowhere, a hand shoots out between the two of them, physically breaking the tension between them.

“Please excuse him, my dear King of Knights,” the Caster says, smiling.  How dare he make such a soft and weak-willed expression whilst they share the same visage!  “This guy and I are long overdue for some heart to heart.”

The Caster all but drags his other self behind him, leaving Arthur dumbfounded and miffed.

“You!” the Caster growls.  “Must you think only of your amusement and self-satisfaction before anything and anyone else?  This is why people call you a tyrant!”

“Ha!  You know very well that a good king must be a tyrant for the good of his country!  What good is a king if he cannot even satiate the desires in his heart?”

“That may have worked in our time but this is different.  The world is about to end and soon there will be no humanity to rule over.  Ritsuka and the others at Chaldea need every Heroic Servant working in harmony, not baiting each other and bickering like little school children!  Furthermore, you refuse to communicate with Ritsuka!”

“How dare you try to be my moral compass, Caster?” the Archer snarls.  He strides towards his older self.  “Don’t act like you were a saint after the trip.  There were many a time when you wished to abandon Uruk and live an easy life without having to rebuild a nation from the ground up.”

“But I didn’t,” Caster rebuts.  “I stayed and made sure that the country and the people I loved would prosper long after the Age of Gods.  You on the other hand only wanted to abuse your power as king and take what you wanted whenever you wanted.”

“A true King needs no rules.  What I deemed right was law,” Archer smirks.   “Besides, how can you call yourself the King of Heroes when you visit a mongrel nightly to siphon mana off of him directly?  What pathetic fool you are, Caster.”

Caster scoffs.  “A counter you should hardly be making.  Need I remind you about a priest you led astray named Kotomine Kirei?”

Archer’s eyes narrow.    “I am a man after all.  I had carnal desires even in this pathetic approximation of a body.  Kotomine Kirei was the object of my intrigue at the time who served his purpose well.”

“Liar,” the Caster counters.  It is he who takes a step towards the Archer this time, positioning himself within centimetres of the Archer’s body.  “You felt something beyond intrigue for that false priest.  It is hard to spend a decade with another person without developing some feelings, be it in the positive or negative direction.”

“You’ve gone senile.  What you think is love for that mongrel Master has turned you into an imbecilic mongrel yourself.”

“I know you, Archer.  I am the grown-up version of you, remember?  I can see that you’re mad because I see through your bullshit.”

Gate of Babylon opens up around the Caster, several portals readied with Noble Phantasms around his head.

“Rash, quick-tempered, and selfish.  You are as child-like as the goddess Ishtar that you rejected,” Caster lists off.  “I think _our_ child version is wiser than you are.”

“Bastard!”

As the Archer is about to grab for his Ea, a hand belonging to neither of the two kings slices the air between them.

“Your Majesty!”  Oh, it’s the mongrel Master that Caster is so fond of.  “Please quell your anger!”

The measly human flinches when he is glared at.  At the same time, he has the look of someone who has been captivated by Gilgamesh’s accursed charisma.

“Yes, please do.  Throw a temper tantrum and you shall prove that you are no better than a child!” Caster exclaims.

“Hmph!” Archer recalls his weapons.  The Gates close.  The mongrel lets out a loud sigh of relief.

“What is going on?” a familiar voice sounds down the corridor.

“A faker shan’t intrude on a confrontation between two true heroes,” the golden Archer lectures.

“Shall I show you once again that a faker can be as good as the real deal?” Emiya snaps. 

“Enough already!” Caster shouts.  His voice carries the power of King, one that suffices to freeze both Archers in their place and have the Master fall to his knees.  “This has been going on long enough!  I don’t care about what happened in Fuyuki during the Fifth War!  Here, we all work together to preserve humanity.  No petty fights, no provocations that were uncalled for, and no acting like the king of the multiverse!  If you can’t act like a grown-up, I’m sure that the staff at Chaldea shall gladly send your ass back to the Throne!”

 

 

 

~

 

 

 

Three nights have passed since Caster Gilgamesh’s ultimatum.  In truth, Ritsuka knew that it was an easy matter for Archer Gilgamesh to have returned to the Throne by himself if he so wished.  Something was keeping him here in the current era, though.  Caster mentioned that it must be curiosity, and Emiya seemed to think it was out of animosity and rivalry; towards whom, he did not specify.

“Forget about that sore loser,” Caster croons, his hands kneading the tension out of Ritsuka’s shoulders and neck.  “He’ll sulk by himself until he is ready to be a grown-up about the whole thing.  If not, whatever.  You need not worry your pretty little head over that jerk.”

Ritsuka sighs.  “It’s hard not to.  All the other Servants have been on high alert since his arrival.  Gawain grows more restless by the day as does Arthur.  I’ve been leading some sim missions to use up their energy but that hardly seems to take their mind off the issue.”

Gil kisses Ritsuka on the back of his neck by the short tufts of hair.  “Worry not, my little Master.  They are knights and warriors, who by nature are muscle-heads.  Give them sufficient time and the issue shall cool itself.”

“Uhm, I don’t think it’s nice to treat them like jocks,” Ritsuka says.

Chuckling, the Caster cues his Master to turn and face him.  The young Magus is frowning adorably, the small crease between his brows just asking to be soothed away with kisses.   Which is precisely what the king does.  He finds Ritsuka pouting when he withdraws after one swift kiss.

“I wish you could just kiss all my worries away,” Ritsuka confesses, burying his face in the folds of Gil’s clothes.  “My life would be easier that way.”

“Yes, and in that sort of world, you would never grow as a person.”

The pout persists.  “There you go again, always with the wise words.”

Gil laughs.  “If you wish to be coddled like a baby, go home to your mother.  I am your Servant and lover.  It is my duty to help you learn.”

Ritsuka peeks out so that only his twinkling blue eyes are visible.  “And what are you gonna teach me today, sensei?”

“That,” Gil purrs, “is entirely up to the aptitude of my student, of course.”

 

**Author's Note:**

> shit end but I just wanted to post something. 
> 
> I've been back from Korea for two weeks now and also moved from Edmonton back to Vancouver-ish. It's been a long summer already and I need to start thinking about what to do this autumn. 
> 
> I'll probably go back to being gloom and doom with Kirei and Gil in the next one, who knows . . .
> 
>  
> 
>  
> 
> [tumblr1](http://www.gilganyan-24.tumblr.com)
> 
>  
> 
> [tumblr2](http://www.riderkarna-24.tumblr.com)


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